1. Chapter 3: The Biosphere
What is ecology?

2. Ecology
Ecology – the study of interactions among organisms and between organisms and their environment
Interdependence – dependence of every form of life on other living things and natural resources (air, water, land) in its environment

3. Levels of Organization
Biosphere – largest, portions of planet where life exists (land, H2O, air)
8 km above to 11 km below
Biome – group of ecosystems with same climate (temp. and rainfall)
Ecosystem – collection of all organisms in a particular place together with the abiotic (physical) environment.

4. Levels of Organization
Community – groups of different populations that live together in a defined area.
Population – groups of individuals of same species in same area.
Species – group of organisms so similar that they can mate and produce fertile offspring.

5. Levels of Organization

6. Biotic and Abiotic Factors
Biotic – living
Plants, Animals ,Mold, Fungi, Bacteria, Protist
Abiotic – Non living
Sunlight, soil, wind, water, temperature
Habitat – the area where an organism lives; includes both biotic and abiotic factors.

7. 3.2 Energy - Autotrophs (producers)
Can trap light energy to produce food (organic molecules)
Plants
Some protists
Some bacteria
Photosynthesis – captures solar energy and converts it to chemical energy
6CO2 + 6H2O C6H12O6 + 6O2
Chemosynthesis – Chemical energy used to produce carbohydrates
SUN

8. 3.2 Energy - Heterotrophs (consumers)
Can’t trap energy directly; must acquire it from other organisms
Herbivores – plants
Carnivores – animals
Omnivores – both
Detritivores – remains of dead plants & animals
Decomposers – break down organic matter

9. 3.3 Energy Flow in Ecosystems
Food Chains and Food Webs

10. 3.3 Food Chains and Food Webs
SUN Autotrophs Heterotroph
Food Chain – energy trapped by producers passed on when organisms eat and are eaten
Food Web – relationship more complex than a chain

11. Trophic Levels and Ecological Pyramids
Trophic Levels – each step in a food chain/web
Ex: producers, then consumers
Ecological Pyramids – shows relative amount of energy at each level (10% rule)
Biomass – total amount of living tissue within a trophic level

12. Trophic Levels and Ecological Pyramids

13. 3.4 Cycles of Matter
*Recycle Matter*

14. Carbon Cycle Photosynthesis – uses CO2 from atmosphere
Happens in the CHLOROPLAST
Respiration – returns CO2 to atmosphere
Happens in the MITOCHONDRIA

15. Carbon Cycle

16. The Carbon Cycle
Volcanoes, respiration, fossil fuels, and decomposition add CO2 to atmosphere.
Plants take CO2 and make carbohydrates
Plants are eaten by animals and carbohydrates are passed through the food chain.
As the animal breathes and eventually dies and decomposes CO2 is return to atmosphere.
Decomposing Fox

17. Water Cycle

18. Water Cycle Water enters the atmosphere by:
Evaporation – water changes from a liquid to a gas
Transpiration – Evaporation through leaves
As water rises it cools condenses into tiny droplets that form clouds.
Droplets return to Earth as precipitation.
Water enters the rivers, ground water, ocean or plant roots to restart cycle.
Making Clouds

19. Nitrogen Cycle

20. Nitrogen Cycle Nitrogen gas makes up 78% of atmosphere
Nitrogen Fixation: bacteria take nitrogen gases and turn it into ammonia, nitrite, and nitrate.
Plants and animals use nitrate to make amino acids.
Animal dies and decomposes returning nitrates to the soil.
Denitrification: other bacteria convert nitrates into nitrogen gas.
Fertilizer Runoff

21. Nutrient Limitation
Primary Productivity – the rate at which organic molecules are created by producers
If nutrients are in short supply, they are called LIMITING NUTRIENTS
Ex: Nitrogen is often limiting in water; if there is suddenly as input of N (fertilizer runoff), organisms can grow rapidly (Algal Bloom)

22. 4-2 Niches and Community Interactions

23. 4.2 The Niche Niche – Where and How something lives; its role
Habitat is the organism’s address
Niche is the organism’s occupation

24. Community Interactions
Competition
Organisms compete for resources
Ex: Food, Mates, Shelter
Competitive Exclusion Principle – no 2 organisms occupy same niche at same time.
Predation
One organism (predator) captures and feeds on another (prey).
Battle at Kruger Lake

25. 4.2 Community Interactions
Symbiosis
Mutualism – both benefit
Ex: Flowers & insects
Egrets & Alligators
Clown Fish & Sea Anemone
Commensalism – one benefits, the other is not helped nor harmed
Ex: Barnacle & Whale
Parasitism – one benefits, other is harmed
Ex: tapeworms, fleas, ticks, lice

26. Otters and Kelp Dung Beetle
Keystone Species – essential to the balance of an ecosystem, change in their population can cause a dramatic change in the community.
Dung Beetle
Otters and Kelp 26

27. 4.3 Ecological Succession
Ecological Succession - change in an ecosystem
Primary Succession – no soil (volcanic eruption or bare rock)
first to appear are “pioneer species” Ex: Lichens
Secondary Succession – Soil Exists (wild fires, clear cutting, plowed for farming)
Succession in a Marine Ecosystem – happens when a large whale dies and sinks to the bottom
Climax Community – fairly stable, mature, dominant community established after succession.

28. Human Impacts
Look at each of the cycles in your notes. In each
cycle there is at least one to two ways that imbalance
can occur.
Identify the sources of imbalance and in particular how human activities upset the cycles.
Explain how this imbalance impacts the cycle and potential ecological problems that could result.
You should identify at least one imbalance for each cycle (water, nitrogen, and carbon)?
Each table group will turn in one paper with your answers.